Interferon-beta treatment eliminates cardiotropic viruses and improves left ventricular function in patients with myocardial persistence of viral genomes and left ventricular dysfunction

Viral Myocarditis-Incidence, Diagnosis and Management

Viral myocarditis has an incidence rate of 10 to 22 per 100,000 individuals. The presentation pattern of viral myocarditis can range from nonspecific symptoms of fatigue and shortness of breath to more aggressive symptoms that mimic acute coronary syndrome. After the initial acute phase presentation of viral myocarditis, the virus may be cleared, resulting in full clinical recovery; the viral infection may persist; or the viral infection may lead to a persistent autoimmune-mediated inflammatory process with continuing symptoms of heart failure. As a result of these 3 possibilities, the diagnosis, prognosis, and treatment of viral myocarditis can be extremely unpredictable and challenging for the clinician. Herein, the incidence, etiology, definition and classification, clinical manifestation, diagnosis, pathogenesis, prognosis, and treatment of viral myocarditis are reviewed, and how acute clinical care teams might differentiate between viral myocarditis and other acute cardiac conditions is discussed.

Recognition and Initial Management of Fulminant Myocarditis: A Scientific Statement From the American Heart Association

Fulminant myocarditis (FM) is an uncommon syndrome characterized by sudden and severe diffuse cardiac inflammation often leading to death resulting from cardiogenic shock, ventricular arrhythmias, or multiorgan system failure. Historically, FM was almost exclusively diagnosed at autopsy. By definition, all patients with FM will need some form of inotropic or mechanical circulatory support to maintain end-organ perfusion until transplantation or recovery. Specific subtypes of FM may respond to immunomodulatory therapy in addition to guideline-directed medical care. Despite the increasing availability of circulatory support, orthotopic heart transplantation, and disease-specific treatments, patients with FM experience significant morbidity and mortality as a result of a delay in diagnosis and initiation of circulatory support and lack of appropriately trained specialists to manage the condition. This scientific statement outlines the resources necessary to manage the spectrum of FM, including extracorporeal life support, percutaneous and durable ventricular assist devices, transplantation capabilities, and specialists in advanced heart failure, cardiothoracic surgery, cardiac pathology, immunology, and infectious disease. Education of frontline providers who are most likely to encounter FM first is essential to increase timely access to appropriately resourced facilities, to prevent multiorgan system failure, and to tailor disease-specific therapy as early as possible in the disease process.

Acute Myocardial Infarction in Young Individuals

Globally, cardiovascular disease remains a major cause of adverse outcomes in young individuals, unlike its decline in other age groups. This group is not well studied and has a unique risk profile with less traditional cardiovascular risk factors compared with older populations. Plaque rupture still remains the most common etiology of myocardial infarction, but unique syndromes such as plaque erosion, coronary microvascular dysfunction, spontaneous coronary artery dissection, and coronary spasm related to drug use are more prevalent in this age group. Such diversity of diagnosis and presentation, along with therapeutic implications, underscore the need to study the profile of myocardial infarction in young persons. We searched PubMed for articles published from 1980 to 218 using the terms acute myocardial infarction, young, plaque rupture, plaque erosion, spontaneous coronary artery dissection (SCAD), coronary vasospasm, variant or Prinzmetal angina, drug-induced myocardial infarction, myocarditis, coronary embolism, microvascular dysfunction, MINOCA, and myocardial infarction in pregnancy and reviewed all the published studies. With the data from this search, we aim to inform readers of the prevalence, risk factors, presentation, and management of acute myocardial infarction in young patients and elaborate on special subgroups with diagnostic and therapeutic challenges. We also outline a parsimonious method designed to simplify management of these complex patients.

Inflammation in myocardial disease: From myocarditis to dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is a heterogeneous group of myocardial diseases clinically defined by the presence of left ventricular dilatation and contractile dysfunction. Among various causes of DCM, a progression from viral myocarditis to DCM has long been hypothesized. Supporting this possibility, studies by endomyocardial biopsy, the only method to obtain a definite diagnosis of myocarditis at present, have provided evidence of inflammation in the myocardium in DCM patients. A number of experimental studies have elucidated a cell-mediated autoimmune mechanism triggered by viral infection in the progression of myocarditis to DCM. In addition, the important role of inflammation in the pathogenesis of heart failure has been recognized, and many terms including myocarditis, inflammatory cardiomyopathy, and inflammatory DCM have been used for myocardial diseases associated with inflammation. This review discusses the pathophysiology of inflammation in the myocardium, and refers to diagnosis and treatment based on these concepts.

Myocarditis: somethings old and something new

"Since the pathological conditions take place at the cellular level, viral myocarditis and postinfectious autoimmunity can be suggested but not diagnosed clinically. All clinical methods including imaging techniques are misleading if infectious agents are involved. Accurate diagnosis demands simultaneous histologic, immunohistochemical, and molecular biological workup of the tissue. If the primary infectious or immune-mediated causes of the disease are carefully defined by clinical and biopsy-based tools, specific antiviral treatment options in addition to basic symptomatic therapy are available under certain conditions. These may allow a tailored cause-specific treatment that improves symptoms and prognosis of patients with acute and chronic disease." Uwe Kühl; Heinz-Peter SchultheissViral myocarditis.Swiss Medical Weekly. 144():w14010, JAN 2014 DOI:10.4414/smw.2014.14010.

Therapeutic Advances in Emergency Cardiology: A Focus on Acute Myocarditis

BACKGROUND

Myocarditis, defined as an inflammation of the myocardium, is an important cause of dilated cardiomyopathy and congestive heart failure. Unfortunately, its diagnosis and etiology is often challenging in clinical practice, and thus, improving diagnosis and therapeutic approach of this cardiac pathology is a matter of great interest.

AREAS OF UNCERTAINTY

The etiology of the disease may be represented by not only infectious agents, usually with viral determination, but also autoimmune and systemic diseases or drugs. Regarding diagnostic techniques, endomyocardial biopsy remains the gold standard; but beyond histological findings, an important step in achieving an accurate diagnosis was represented by the use immunohistochemical criteria and noninvasive diagnostic tests such as cardiac magnetic resonance imaging.

DATA SOURCES

We reviewed current data on the current diagnosis and therapeutic approach of acute myocarditis.

THERAPEUTIC ADVANCES

In addition to the standard heart failure therapy, some specific therapeutic options are available in selected cases. Viral myocarditis with persistent inflammation and viral clearance may be responsive to immunosuppressive therapy with azathioprine and cortisone or to immunoadsorption technique. Also, some chronic viral myocardial infections may benefit from 6 months of interferon-β therapy.

CONCLUSIONS

The diagnosis of acute myocarditis still remains a great challenge, despite advances related to new diagnostic procedures. Endomyocardial biopsy, an invasive diagnostic tool that is not always usually available in clinical practice, still remains the standard diagnostic technique. Due to the potential evolution of acute myocarditis, identifying new parameters that may allow an early selection of patients with great risk of evolution toward myocardial fibrosis and dilated cardiomyopathy may be a field of great interest for future studies.

Viral myocarditis: a prime example for endomyocardial biopsy-guided diagnosis and therapy

Purpose of review

Myocarditis is an inflammatory disease of the cardiac muscle mainly caused by viral infection. Due to the diverse clinical presentation of myocarditis, accurate diagnosis demands simultaneous histologic, immunohistochemical and molecular biological workup of endomyocardial biopsies (EMBs) as defined by the position statement of the Working Group on Myocardial and Pericardial Diseases of the European Society of Cardiology on myocarditis.

Recent findings

Endomyocardial biopsy-based analysis of viral transcriptional activity, mRNA expression, epigenetics and region-specific protein expression analysis via imaging mass spectrometry have led to the identification of novel potential diagnostic criteria, markers with prognostic value and therapeutic targets for the treatment of viral myocarditis, opening new avenues for novel therapies, including cell therapies, as well as the use of established treatment options, be it from other indications.

Summary

Under certain clinical scenarios EMB-based analysis is required to come to a tailored individualized therapy that improves symptoms and prognosis of patients with acute and chronic viral-driven cardiac inflammation.

Myocarditis in Humans and in Experimental Animal Models

Myocarditis is defined as an inflammation of the cardiac muscle. In humans, various infectious and non-infectious triggers induce myocarditis with a broad spectrum of histological presentations and clinical symptoms of the disease. Myocarditis often resolves spontaneously, but some patients develop heart failure and require organ transplantation. The need to understand cellular and molecular mechanisms of inflammatory heart diseases led to the development of mouse models for experimental myocarditis. It has been shown that pathogenic agents inducing myocarditis in humans can often trigger the disease in mice. Due to multiple etiologies of inflammatory heart diseases in humans, a number of different experimental approaches have been developed to induce myocarditis in mice. Accordingly, experimental myocarditis in mice can be induced by infection with cardiotropic agents, such as coxsackievirus B3 and protozoan parasite Trypanosoma cruzi or by activating autoimmune responses against heart-specific antigens. In certain models, myocarditis is followed by the phenotype of dilated cardiomyopathy and the end stage of heart failure. This review describes the most commonly used mouse models of experimental myocarditis with a focus on the role of the innate and adaptive immune systems in induction and progression of the disease. The review discusses also advantages and limitations of individual mouse models in the context of the clinical manifestation and the course of the disease in humans. Finally, animal-free alternatives in myocarditis research are outlined.

Cardio-Immunology of Myocarditis: Focus on Immune Mechanisms and Treatment Options

Myocarditis and inflammatory cardiomyopathy are syndromes, not aetiological disease entities. From animal models of cardiac inflammation we have detailed insight of the strain specific immune reactions based on the genetic background of the animal and the infectiosity of the virus. Innate and adaptive immunity also react in man. An aetiological diagnosis of a viral vs. a non-viral cause is possible by endomyocardial biopsy with histology, immunohistology and PCR for microbial agents. This review deals with the different etiologies of myocarditis and inflammatory cardiomyopathy on the basis of the genetic background and the predisposition for inflammation. It analyses the epidemiologic shift in cardiotropic viral agents in the last 30 years. Based on the understanding of the interaction between infection and the players of the innate and adaptive immune system it summarizes pathogenetic phases and clinical faces of myocarditis. It gives an up-to-date information on specific treatment options beyond symptomatic heart failure and antiarrhythmic therapy. Although inflammation can resolve spontaneously, specific treatment directed to the causative etiology is often required. For fulminant, acute, and chronic autoreactive myocarditis without viral persistence immunosuppressive treatment can be life-saving, for viral inflammatory cardiomyopathy ivIg treatment can resolve inflammation and often eradicate the virus.

Biphasic and cardiomyocyte-specific IFIT activity protects cardiomyocytes from enteroviral infection

Viral myocarditis is a serious disease, commonly caused by type B coxsackieviruses (CVB). Here we show that innate immune protection against CVB3 myocarditis requires the IFIT (IFN-induced with tetratricopeptide) locus, which acts in a biphasic manner. Using IFIT locus knockout (IFITKO) cardiomyocytes we show that, in the absence of the IFIT locus, viral replication is dramatically increased, indicating that constitutive IFIT expression suppresses CVB replication in this cell type. IFNβ pre-treatment strongly suppresses CVB3 replication in wild type (wt) cardiomyocytes, but not in IFITKO cardiomyocytes, indicating that other interferon-stimulated genes (ISGs) cannot compensate for the loss of IFITs in this cell type. Thus, in isolated wt cardiomyocytes, the anti-CVB3 activity of IFITs is biphasic, being required for protection both before and after T1IFN signaling. These in vitro findings are replicated in vivo. Using novel IFITKO mice we demonstrate accelerated CVB3 replication in pancreas, liver and heart in the hours following infection. This early increase in virus load in IFITKO animals accelerates the induction of other ISGs in several tissues, enhancing virus clearance from some tissues, indicating that–in contrast to cardiomyocytes–other ISGs can offset the loss of IFITs from those cell types. In contrast, CVB3 persists in IFITKO hearts, and myocarditis occurs. Thus, cardiomyocytes have a specific, biphasic, and near-absolute requirement for IFITs to control CVB infection.

Viruses can infect the heart, causing inflammation–termed myocarditis–which is a serious, and sometimes fatal, disease. One way to combat the infection is by stimulating our immune system, encouraging it to fight the virus. However, the treatment that is currently used “revs up” many different parts of our immune system, including some that play little or no role in clearing the virus, and this wide-ranging activation increases the risk of potentially-harmful side effects. We want to identify the parts of the immune system that fight virus infections of the heart, so that we can improve the treatment of viral myocarditis by selectively stimulating only those immune responses, thereby retaining the benefit of treatment (i.e., clearing the virus) while reducing its cost (i.e. lowering the risk of harmful side effects). In this paper, we demonstrate that a family of proteins called IFITs play a role in protecting many tissues against these infections, but are particularly important in heart muscle cells, in which they are indispensable. Thus, IFITs represent a possible target for the treatment of viral myocarditis.

Dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is a clinical diagnosis characterized by left ventricular or biventricular dilation and impaired contraction that is not explained by abnormal loading conditions (for example, hypertension and valvular heart disease) or coronary artery disease. Mutations in several genes can cause DCM, including genes encoding structural components of the sarcomere and desmosome. Nongenetic forms of DCM can result from different aetiologies, including inflammation of the myocardium due to an infection (mostly viral); exposure to drugs, toxins or allergens; and systemic endocrine or autoimmune diseases. The heterogeneous aetiology and clinical presentation of DCM make a correct and timely diagnosis challenging. Echocardiography and other imaging techniques are required to assess ventricular dysfunction and adverse myocardial remodelling, and immunological and histological analyses of an endomyocardial biopsy sample are indicated when inflammation or infection is suspected. As DCM eventually leads to impaired contractility, standard approaches to prevent or treat heart failure are the first-line treatment for patients with DCM. Cardiac resynchronization therapy and implantable cardioverter-defibrillators may be required to prevent life-threatening arrhythmias. In addition, identifying the probable cause of DCM helps tailor specific therapies to improve prognosis. An improved aetiology-driven personalized approach to clinical care will benefit patients with DCM, as will new diagnostic tools, such as serum biomarkers, that enable early diagnosis and treatment.

Proteasomal Protein Degradation: Adaptation of Cellular Proteolysis With Impact on Virus-and Cytokine-Mediated Damage of Heart Tissue During Myocarditis

Viral myocarditis is an inflammation of the heart muscle triggered by direct virus-induced cytolysis and immune response mechanisms with most severe consequences during early childhood. Acute and long-term manifestation of damaged heart tissue and disturbances of cardiac performance involve virus-triggered adverse activation of the immune response and both immunopathology, as well as, autoimmunity account for such immune-destructive processes. It is a matter of ongoing debate to what extent subclinical virus infection contributes to the debilitating sequela of the acute disease. In this review, we conceptualize the many functions of the proteasome in viral myocarditis and discuss the adaptation of this multi-catalytic protease complex together with its implications on the course of disease. Inhibition of proteasome function is already highly relevant as a strategy in treating various malignancies. However, cardiotoxicity and immune-related adverse effects have proven significant hurdles, representative of the target's wide-ranging functions. Thus, we further discuss the molecular details of proteasome-mediated activity of the immune response for virus-mediated inflammatory heart disease. We summarize how the spatiotemporal flexibility of the proteasome might be tackled for therapeutic purposes aiming to mitigate virus-mediated adverse activation of the immune response in the heart.

Viral genome changes and the impact of viral genome persistence in myocardium of patients with inflammatory cardiomyopathy

INTRODUCTION

Viral infections are considered the most frequent cause of myocarditis and dilated cardiomyopathy (DCM).

MATERIAL AND METHODS

We investigated the changes in viral presence and the impact of viral genome persistence in the myocardium on echocardiographic parameters, functional status and some laboratory parameters in a 6-month follow-up. Fifty-four patients with recent onset DCM, left ventricular ejection fraction < 40% and biopsy-proven myocarditis (> 14 mononuclear leukocytes/mm² and/or > 7 T-lymphocytes/mm²) were enrolled. Polymerase chain reaction (PCR) was performed to detect pathogens in the myocardium. Patients were divided according to the administered therapy: standard heart failure medication (46 patients) and immunosuppressive therapy (8 patients).

RESULTS

In the standard heart failure medication group viral clearance was observed in 13 patients and viral persistence in 24 patients in the follow-up period. Comparing both groups, there was no statistically significant difference - LVEF improvement of 12.0 ±11.4% vs. 18.3 ±12.6%, decrease in NYHA class of 0.7 ±0.7 vs. 1.0 ±0.7, decline in NT-proBNP of 1335 ±1933 ng/l vs. 1942 ±3242 ng/l and decrease in infiltrating leukocytes of 11.1 ±15.8 vs. 6.7 ±23.0 cells/mm² and T-lymphocytes of 5.8 ±15.1 vs. 1.8 ±10.9 cells/mm² (all p = NS). A decrease in PCR positive patients from 37 to 29 was observed. The number of PVB19 positive PCR findings decreased from 5 to 4 in patients with immunosuppressive therapy.

CONCLUSIONS

A decrease in the number of positive PCR findings in control endomyocardial biopsy was observed. Viral genome persistence was not associated with worse outcome in short-term follow-up.

CCR5del32 genotype in human enteroviral cardiomyopathy leads to spontaneous virus clearance and improved outcome compared to wildtype CCR5

Background

Enteroviral cardiomyopathy is a life-threatening disease, and detection of enterovirus (EV) RNA in the initial endomyocardial biopsy is associated with adverse prognosis and increased mortality. Some patients with EV infection may spontaneously eliminate the virus and recover, whereas those with virus persistence deteriorate and progress to heart failure. Interferon-beta (IFN-β) therapy eliminates the virus, resulting in increased survival of treated patients. CCR5 is expressed on antigen-presenting cells (both macrophages and dendritic cells) and immune effector cells (T-lymphocytes with memory/effector phenotype and natural killer cells). Its 32-bp deletion (CCR5del32) is the most frequent human coding sequence mutation. This study addresses the correlation of CCR5 polymorphism to the clinical course of EV infection and the necessity for IFN-β treatment.

Methods

We examined 97 consecutive patients with chronic/inflammatory cardiomyopathy and biopsy-proven EV infection and reliable information on clinical outcomes by CCr5 genotyping. These data were evaluated in relation to virus persistence in follow-up biopsies and survival rates over a 15-year period.

Results

Genotyping revealed a strong correlation between the CCR5del32 genotype and spontaneous virus clearance with improved outcomes. All patients with CCR5del32 eliminated EV spontaneously and none of them died within the observed period. In the group of untreated CCR5 wildtype patients, 33% died (Kaplan–Meier log-rank p = 0.010). However, CCR5 wildtype individuals treated with IFN-β are more likely to survive than without therapy (Kaplan–Meier log-rank p = 0.004) in identical proportions to individuals with the CCR5del32 genotype.

Conclusions

These data suggest that CCR5 genotyping is a novel predictive genetic marker for the clinical course of human EV cardiomyopathies. Hereby clinicians can identify those EV positive individuals who will eliminate the virus spontaneously based on CCR5 phenotype and those patients with CCR5 wildtype genotype who would be eligible for immediate antiviral IFN-β treatment to minimize irreversible cardiac damage.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1610-8) contains supplementary material, which is available to authorized users.

The MOGE(S) classification for cardiomyopathies: current status and future outlook

Cardiomyopathies are complex diseases of multifactorial pathogenesis and have a high morbidity and mortality. Over the past decades, several revisions of classifications and definitions of cardiomyopathies have been proposed, primarily focusing on the phenotypic characterization of cardiomyopathies. The MOGE(S) classification system published in 2013 encompasses the classification of rapidly growing knowledge on genetic mutations, acquired causes (i.e., intramyocardial inflammation, viral infections), and further conditions involved in the induction of cardiomyopathies (e.g., storage diseases, toxicity). It is based on five attributes, including morphofunctional characteristics (M), organ involvement (O), genetic or familial inheritance pattern (G), etiological annotation (E), and optional information about the heart failure functional status (S). This review summarizes the development, the cornerstones of the MOGE(S) classification, and the published data on the clinical relevance of the MOGE(S) classification. We furthermore discuss new issues which might be considered for future updates of the MOGE(S) classification of cardiomyopathies.

Cardiovascular Involvement in Chronic Hepatitis C Virus Infections - Insight from Novel Antiviral Therapies

Whereas statistical association of hepatitis C virus (HCV) infection with cardiomyopathy is long known, establishment of a causal relationship has not been achieved so far. Patients with advanced heart failure (HF) are mostly unable to tolerate interferon (IFN)-based treatment, resulting in limited experience regarding the possible pathogenic role of HCV in this patient group. HCV infection often triggers disease in a broad spectrum of extrahepatic organs, with innate immune and autoimmune pathogenic processes involved. The fact that worldwide more than 70 million patients are chronically infected with HCV illustrates the possible clinical impact arising if cardiomyopathies were induced or aggravated by HCV, resulting in progressive HF or severe arrhythmias. A novel path has been opened to finally resolve the long-standing question of cause-effect relationship between HCV infection and cardiac dysfunction, by the recent development of IFN-free, highly efficient, and well tolerable anti-HCV regimens. The new direct-acting antiviral (DAA) agents are highly virus-specific and lack unspecific side-effects upon cardiac function which have always confounded the interpretation of IFN treatment data. The actual frequency of unexplained HF in chronic HCV infection will be determined from a planned large-scale study. Whereas such patients probably constitute a rather small fraction of all those harboring HCV, they have major clinical relevance. It is not yet known which fraction of these patients will significantly benefit from HCV eradication, but this issue will be addressed now in a prospective study.

The emerging role of cardiovascular magnetic resonance imaging in the assessment of cardiac involvement in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is the commonest rheumatic disease in childhood and presents several subtypes according to the ILAR classification. JIA, specifically in its systemic form, may seriously damage various structures of the cardiovascular system. Other JIA phenotypes are also of interest, as cardiovascular disease (CVD) is underestimated and understudied, but chronic systemic inflammation and risk factors remained important contributors for CVD development. The currently applied non-invasive modalities, although they are important for the initial evaluation of JIA patients, frequently fail to detect the silent, subclinical forms of CVD. Cardiovascular magnetic resonance (CMR), due to its multifaceted capability in the detection of cardiovascular disease, can offer early, reproducible, non-invasive information about cardiovascular disease in JIA, allowing risk stratification and timely initiation /modification of cardiologic and anti-rheumatic treatment. However, lack of availability/expertise and high cost still hamper its application in the clinical cardio-rheumatic practice. The aim of the current article is to present an overview of CVD in JIA emphasizing the emerging role of CMR in early diagnosis and treatment follow-up of CVD in JIA patients.

Approximation of the Incidence of Myocarditis by Systematic Screening With Cardiac Magnetic Resonance Imaging

OBJECTIVES

This study sought to obtain an approximation of the true incidence of myocarditis by systematic screening of patients at risk using cardiac magnetic resonance imaging (CMR) in a tertiary care center.

BACKGROUND

Underdiagnosis of myocarditis and resulting uncertainty about its incidence remain a clinical dilemma. The authors hypothesized that systematic screening of patients presenting with angina-like symptoms, elevated troponin T, and no significant coronary artery disease using CMR will provide an approximation of the true incidence of myocarditis.

METHODS

The authors performed a retrospective chart review of patients presenting with angina-like symptoms and elevated high-sensitivity troponin T (TnT-hs ≥14 ng/l) in 2015 and 2016. During the year 2015, only patients with elevated TnT-hs, no significant coronary artery disease, and moderate-to-high clinical likelihood of myocarditis underwent CMR. Starting in 2016, CMR was obtained in patients with similar presentation, but independent of clinical likelihood of myocarditis.

RESULTS

A total of 1,788 patients (74% male, age 69 ± 14 years) qualified for our analysis. In 2015, 521 patients presented with angina-like symptoms and TnT-hs elevation. In 2016, the number increased to 1,267 patients. Although in the year 2015, a total of 4 of 88 (5%) CMRs were positive for myocarditis, the percentage of positive CMRs doubled (26 of 199; 13%; p = 0.03) in 2016.

CONCLUSIONS

A novel diagnostic screening algorithm led to a 6.3-fold increase of the incidence of myocarditis in our hospital. Furthermore, the percentage of CMRs positive for myocarditis doubled, supporting the diagnostic value of this method. Considering the potentially lethal adverse events of myocarditis if left untreated, we recommend a low threshold for the use of CMR in patients with angina-like symptoms and elevated TnT-hs after exclusion of coronary artery disease.

NF-κB-mediated metabolic remodelling in the inflamed heart in acute viral myocarditis

Acute viral myocarditis (VM), characterised by leukocyte infiltration and dysfunction of the heart, is an important cause of sudden cardiac death in young adults. Unfortunately, to date, the pathological mechanisms underlying cardiac failure in VM remain incompletely understood. In the current study, we investigated if acute VM leads to cardiac metabolic rewiring and if this process is driven by local inflammation. Transcriptomic analysis of cardiac biopsies from myocarditis patients and a mouse model of VM revealed prominent reductions in the expression of a multitude of genes involved in mitochondrial oxidative energy metabolism. In mice, this coincided with reductions in high-energy phosphate and NAD levels, as determined by Imaging Mass Spectrometry, as well as marked decreases in the activity, protein abundance and mRNA levels of various enzymes and key regulators of cardiac oxidative metabolism. Indicative of fulminant cardiac inflammation, NF-κB signalling and inflammatory cytokine expression were potently induced in the heart during human and mouse VM. In cultured cardiomyocytes, cytokine-mediated NF-κB activation impaired cardiomyocyte oxidative gene expression, likely by interfering with the PGC-1 (peroxisome proliferator-activated receptor (PPAR)-γ co-activator) signalling network, the key regulatory pathway controlling cardiomyocyte oxidative metabolism. In conclusion, we provide evidence that acute VM is associated with extensive cardiac metabolic remodelling and our data support a mechanism whereby cytokines secreted primarily from infiltrating leukocytes activate NF-κB signalling in cardiomyocytes thereby inhibiting the transcriptional activity of the PGC-1 network and consequently modulating myocardial energy metabolism.

[Inflammatory cardiomyopathy and myocarditis]

We describe diagnosis, differential diagnosis, multimodality imaging and medical and invasive diagnostic treatment in patients with inflammatory cardiomyopathy and myocarditis under etiological considerations in reference to a landmark position paper of the Working Group Myocardial and Pericardial Diseases of the European Society of Cardiology together with recent developments in diagnosis and treatment. Diagnosis of the symptomatic patient is the assessment of etiology of inflammatory cardiomyopathy, followed by the clinical presentation, course, treatment option and prognosis. Viral myocarditis in its different facets can clearly be separated from autoreactive forms by histological and molecular methods in the endomyocardial biopsy, thus leading to an individualized targeted therapy beyond heart failure treatment.

'Clinically suspected myocarditis with pseudoinfarct presentation' complicated with left ventricular aneurysm

A 51-year-old man presented with chest pain, high troponin level, inflammatory syndrome and ST-segment elevation in the anterior leads. While the transthoracic echocardiogram (TTE) showed anteroseptal hypokinesis and apical akinesis, the coronary angiogram was normal. Cardiac MR demonstrated a typical aspect of myocarditis (multiple areas of mid-myocardial late gadolinium enhancement, sparing the subendocardial layer, along with oedema). The initial diagnosis was clinically suspected myocarditis with pseudoinfarct presentation. However, the short-term evolution was not typical of this syndrome, since an apical transmural scar with aneurysm developed within 2 weeks. Seven years later, the patient remained asymptomatic, while Q waves persisted in anterior leads along with an apical aneurysm on TTE. A transmural myocardial necrosis with aneurysm is an unusual complication of acute myocarditis. The potential mechanisms accounting for the development of these lesions are reviewed, and the clinical implications for the diagnosis and monitoring of acute myocarditis are discussed.

Viral Infection of the Heart: Pathogenesis and Diagnosis

Viral infections of the heart cause serious clinical problems, either as infectious myocarditis, which usually is a consequence of acute infection or as idiopathic dilated cardiomyopathy, resulting rather from a chronic infection. This minireview presents an up-to-date view on pathomechanisms of viral infection of the heart tissues, the role of immune system in controlling infectious process at its various stages and current possibilities of recognizing viral infection of the heart with use of both cardiological and virological methods. Our goal was to present the variety of known viral agents causing heart infection, level of complexity in mutual virus-cell interactions, and consequent clinical scenarios.

Myocarditis: A Clinical Overview

PURPOSE OF REVIEW

In this paper we will review the modern diagnostic approach to patients with clinically suspected myocarditis as well as the treatment modalities and strategy in light of up-to-date clinical experience and scientific evidence.

RECENT FINDINGS

Rapidly expanding evidence suggests that myocardial inflammation is frequently underdiagnosed or overlooked in clinical practice, although new therapeutic options have been validated. Moreover, the available evidence suggests that subclinical cardiac involvement has negative prognostic impact on morbidity and mortality and should be actively investigated and adequately treated. Myocarditis represents a growing challenge for physicians, due to increased referral of patients for endomyocardial biopsy (EMB) or cardiac magnetic resonance (CMR), and requires a highly integrated management by a team of caring physicians.

Inflammatory Cardiomyopathic Syndromes

Inflammatory activation occurs in nearly all forms of myocardial injury. In contrast, inflammatory cardiomyopathies refer to a diverse group of disorders in which inflammation of the heart (or myocarditis) is the proximate cause of myocardial dysfunction, causing injury that can range from a fully recoverable syndrome to one that leads to chronic remodeling and dilated cardiomyopathy. The most common cause of inflammatory cardiomyopathies in developed countries is lymphocytic myocarditis most commonly caused by a viral pathogenesis. In Latin America, cardiomyopathy caused by Chagas disease is endemic. The true incidence of myocarditis is unknown to the limited utilization and the poor sensitivity of endomyocardial biopsies (especially for patchy diseases such as lymphocytic myocarditis and sarcoidosis) using the gold-standard Dallas criteria. Emerging immunohistochemistry criteria and molecular diagnostic techniques are being developed that will improve diagnostic yield, provide additional clues into the pathophysiology, and offer an application of precision medicine to these important syndromes. Immunosuppression is recommended for patients with cardiac sarcoidosis, giant cell myocarditis, and myocarditis associated with connective tissue disorders and may be beneficial in chronic viral myocarditis once virus is cleared. Further trials of immunosuppression, antiviral, and immunomodulating therapies are needed. Together, with new molecular-based diagnostics and therapies tailored to specific pathogeneses, the outcome of patients with these disorders may improve.

Cardiomyopathies: An Overview

The nonischemic cardiomyopathies are a diverse group of cardiac disorders that frequently cause heart failure and death and are now recognized with increasing frequency. There has been substantial progress in the clinical recognition and understanding of the natural history of these conditions. Well-established and new techniques of cardiac imaging are also helpful in this regard. Basic scientists are elucidating the pathogenesis and pathobiology of individual cardiomyopathies. In this compendium, some of the most important advances in this field are reviewed. Scientific opportunities to enhance further collaborative research to accelerate progress are identified.

Efficiency of immunosuppressive therapy in virus-negative and virus-positive patients with morphologically verified lymphocytic myocarditis

Aim. To evaluate the efficiency of immunosuppressive therapy (IST) in virus-negative (V–) and virus-positive (V+) patients with lymphocytic myocarditis (LM). Subjects and methods. 60 patients (45 males) (mean age 46.7±11.8 years) with dilated cardiomyopathy (mean left ventricular (LV) end diastolic size (EDS) 6.7±0.7 cm; ejection fraction (EF) 26.2±9.1%) were examined. The diagnosis of active/borderline LM was verified by right ventricular endomyocardial biopsy in 38 patients, by intraoperative LV biopsy in 10, in the study of explanted hearts from 3 patients and at autopsy in 9. The investigators determined the genomes of parvovirus B19, herpes viruses types 1, 2 and 6, Epstein—Barr (EBV), zoster, and cytomegalovirus in the blood and myocardium and, if antibodies were present in the blood, hepatitis B and C viruses, as well as antibodies against antigens in the endothelium, cardiomyocytes and their nuclei, smooth muscles, fibers of the conducting system. IST was used in terms of histological, immune, and viral activities. IST was performed in 22 V+ patients (Group 1) and in 24 V– patients (Group 2); this was not done in 10 V+ patients (Group 3) and V– patients (Group 4). IST comprised methylprednisolone at a mean dose of 24 mg/day (n=40), hydroxychloroquine 200 mg/day (n=20), azathioprine at a mean dose of 150 mg/day (n=21); antiviral therapy included acyclovir, ganciclovir, intravenous immunoglobulin (n=24). The follow-up period was 19 (7.3—40.3) months. Results. The viral genome was detected in the myocardium of 32 patients who made up a V+ group. The degree of histological activity did not differ in relation to the presence of viral genome in the myocardium. The degree of immune activity (anticardiolipin antibody titers) in the V+ patients was as high as that in V– ones. At baseline, the V+ patients had a significantly higher LV EDS and a lower EF than the V– patients. Overall, IST only could lead to a significant increase in EF (from 26.5±0.9 to 36.0±10.8%; p

Effect of Chronic Hepatitis C Virus Treatment by Combination Therapy on Cardiovascular System

BACKGROUND

The prevalence of hepatitis C virus (HCV) in Egypt is quite high, and the combined oral direct-acting antiviral agents (DAAs) may have impressive results.

OBJECTIVE

To assess the cardiovascular effects of DAAs in patients with HCV.

METHODS

A total of 170 patients with HCV were divided into 2 groups: first group (100 patients) received triple combination therapy (pegylated interferon alfa, sofosbuvir, and ribavirin, whereas the second group (70 patients) received dual combination therapy (sofosbuvir and simeprevir). Group 1 patients were followed up for 1 year more than 3 visits, whereas group 2 patients were followed up for 6 months more than 2 visits; and the end point of the study was the development of a major cardiovascular event (eg, congestive heart failure, echocardiographic evidence of left ventricular dysfunction, occurrence of significant arrhythmias, or acute coronary syndrome). The following parameters were accomplished: medical history and clinical examination, electrocardiogram, echo-Doppler study, and laboratory investigations.

RESULTS

No significant differences were found between the 2 study groups regarding demographic criteria. None of the both group patients had developed any major cardiac event. No significant changes were observed regarding ST-T wave abnormalities, arrhythmias, or QT interval. None of the both group patients developed echocardiographic regional wall motion abnormalities at baseline or at study end. Systolic function parameters showed minute nonsignificant changes over study visits. Diastolic function parameters showed nonsignificant changes between baseline and 6-month and 12-month visits.

CONCLUSIONS

The DAAs used in combination regimen with interferon or used orally in combination do not significantly affect the cardio-vascular system.

Profiling Subcellular Protein Phosphatase Responses to Coxsackievirus B3 Infection of Cardiomyocytes

Cellular responses to stimuli involve dynamic and localized changes in protein kinases and phosphatases. Here, we report a generalized functional assay for high-throughput profiling of multiple protein phosphatases with subcellular resolution and apply it to analyze coxsackievirus B3 (CVB3) infection counteracted by interferon signaling. Using on-plate cell fractionation optimized for adherent cells, we isolate protein extracts containing active endogenous phosphatases from cell membranes, the cytoplasm, and the nucleus. The extracts contain all major classes of protein phosphatases and catalyze dephosphorylation of plate-bound phosphosubstrates in a microtiter format, with cellular activity quantified at the end point by phosphospecific ELISA. The platform is optimized for six phosphosubstrates (ERK2, JNK1, p38α, MK2, CREB, and STAT1) and measures specific activities from extracts of fewer than 50,000 cells. The assay was exploited to examine viral and antiviral signaling in AC16 cardiomyocytes, which we show can be engineered to serve as susceptible and permissive hosts for CVB3. Phosphatase responses were profiled in these cells by completing a full-factorial experiment for CVB3 infection and type I/II interferon signaling. Over 850 functional measurements revealed several independent, subcellular changes in specific phosphatase activities. During CVB3 infection, we found that type I interferon signaling increases subcellular JNK1 phosphatase activity, inhibiting nuclear JNK1 activity that otherwise promotes viral protein synthesis in the infected host cell. Our assay provides a high-throughput way to capture perturbations in important negative regulators of intracellular signal-transduction networks.

[Myocarditis]

Acute myocarditis must be considered in patients with recent onset of cardiac failure or arrhythmia. Fulminant myocarditis is a distinct entity characterized by sudden onset of severe congestive heart failure or cardiogenic shock, usually following a flu-like illness, parvovirus B19, human herpesvirus 6, coxsackie virus and adenovirus being the most frequently viruses responsible for the disease. In this setting, early recognition of patients rapidly progressing to refractory cardiac failure and their immediate transfer to a medical-surgical center experienced in mechanical circulatory support is warranted. Treatment of acute myocarditis relies on conventional heart failure therapy. Immunosuppression of autoreactive myocarditis or immuno-stimulants such as interferons for chronic viral myocarditis could be of interest but their potential therapeutic role requires further investigation.

Cardiac Autoimmunity: Myocarditis

Myocarditis is the inflammation of the muscle tissues of the heart (myocardium). After a pathologic cardiac-specific inflammatory process, it may progress to chronic damage and dilated cardiomyopathy. The latter is characterized by systolic dysfunction, whose clinical correlate is heart failure. Nevertheless, other acute complications may arise as consequence of tissue damage and electrophysiologic disturbances. Different etiologies are involved in triggering myocarditis. In some cases, such as giant cell myocarditis or eosinophilic necrotizing myocarditis, it is an autoimmune process. Several factors predispose the development of autoimmune myocarditis such as systemic/local primary autoimmunity, viral infection, HLA and gender bias, exposure of cryptic antigens, mimicry, and deficient thymic training/Treg induction. Once the anti-myocardium autoimmune process is triggered, several components of the immune response orchestrate a sustained attack toward myocardial tissues with particular timing and immunopathogenic features. Innate response mediated by monocytes/macrophages, neutrophils, and eosinophils parallels the adaptive response, playing a final effector role and not only a priming function. Stromal cells like fibroblast are also involved in the process through specific cytokines. Furthermore, adaptive T cell responses have anti-paradigmatic features, as Th17 response is dispensable for acute myocarditis but is the main driver of the process leading to dilated cardiomyopathy. Humoral response, thought to be a bystander, is important in the appearance of late-stage hemodynamic complications. The complexity of that process, as well as the unspecific and variable clinical presentation, had generated difficulties for diagnosis and treatment, which remain suboptimal. In this chapter, we will discuss the most relevant immunopathogenic findings from a basic science and clinical perspective.

Human Parvoviruses

Parvovirus B19 (B19V) and human bocavirus 1 (HBoV1), members of the large Parvoviridae family, are human pathogens responsible for a variety of diseases. For B19V in particular, host features determine disease manifestations. These viruses are prevalent worldwide and are culturable in vitro, and serological and molecular assays are available but require careful interpretation of results. Additional human parvoviruses, including HBoV2 to -4, human parvovirus 4 (PARV4), and human bufavirus (BuV) are also reviewed. The full spectrum of parvovirus disease in humans has yet to be established. Candidate recombinant B19V vaccines have been developed but may not be commercially feasible. We review relevant features of the molecular and cellular biology of these viruses, and the human immune response that they elicit, which have allowed a deep understanding of pathophysiology.

Established and novel treatment options in acute myocarditis, with or without heart failure

INTRODUCTION

Acute myocarditis is a disorder characterized by an unpredictable clinical course which ranges from asymptomatic, incidentally discovered forms, to cases with fulminant course and adverse outcome. The most challenging issues in the context of acute myocarditis are the appearance of difficult to treat heart failure in the acute phase and the potential progression in the long-term to dilated cardiomyopathy. Areas covered: With respect to available treatment options in acute myocarditis, in the absence of specific guidelines, management is supportive and overall empirical, especially for the oligo- or asymptomatic patients with preserved ejection fraction. Haemodynamically instable patients should be treated in referral centers with capability of advanced cardiopulmonary support. Patients with heart failure but without haemodynamic impairment should be treated according to the heart failure guidelines. Endomyocardial biopsy may be performed in an individualized basis both for diagnostic purposes and to guide treatment, based on the detection or not of viral genome. Expert commentary: Apart from the already established treatments, novel therapies against several targets are currently investigated and are expected to contribute to a more efficacious management options in the future. Increased awareness among medical professionals is essential for the early diagnosis and best care of acute myocarditis patients.

Coxsackievirus B3 induces the formation of autophagosomes in cardiac fibroblasts both in vitro and in vivo

Coxsackievirus group B (CVB) is one of the common pathogens that cause myocarditis and cardiomyopathy. Evidence has shown that CVB replication in cardiomyocytes is responsible for the damage and loss of cardiac muscle and the dysfunction of the heart. However, it remains largely undefined how CVB would directly impact cardiac fibroblasts, the most abundant cells in human heart. In this study, cardiac fibroblasts were isolated from Balb/c mice and infected with CVB type 3 (CVB3). Increased double-membraned, autophagosome-like vesicles in the CVB3-infected cardiac fibroblasts were observed with electron microscope. Punctate distribution of LC3 and increased level of LC3-II were also detected in the infected cardiac fibroblasts. Furthermore, we observed that the expression of pro-inflammatory cytokines, IL-6 and TNF-α, was increased in the CVB3-infected cardiac fibroblasts, while suppressed autophagy by 3-MA and Atg7-siRNA inhibited cytokine expression. Consistent with the in vitro findings, increased formation of autophagosomes was observed in the cardiac fibroblasts of Balb/c mice infected with CVB3. In conclusion, our data demonstrated that cardiac fibroblasts respond to CVB3 infection with the formation of autophagosomes and the release of the pro-inflammatory cytokines. These results suggest that the autophagic response of cardiac fibroblasts may play a role in the pathogenesis of myocarditis caused by CVB3 infection.

T-cell immunity in myocardial inflammation: pathogenic role and therapeutic manipulation

T-cell-mediated immunity has been linked not only to a variety of heart diseases, including classic inflammatory diseases such as myocarditis and post-myocardial infarction (Dressler's) syndrome, but also to conditions without an obvious inflammatory component such as idiopathic dilated cardiomyopathy and hypertensive cardiomyopathy. It has been recently proposed that in all these conditions, the heart becomes the focus of T-cell-mediated autoimmune inflammation following ischaemic or infectious injury. For example, in acute myocarditis, an inflammatory disease of heart muscle, T-cell responses are thought to arise as a consequence of a viral infection. In a number of patients, persistent T-cell-mediated responses in acute viral myocarditis can lead to autoimmunity and chronic cardiac inflammation resulting in dilated cardiomyopathy. In spite of the major progress made in understanding the mechanisms of pathogenic T-cell responses, effective and safe therapeutic targeting of the immune system in chronic inflammatory diseases of the heart has not yet been developed due to the lack of specific diagnostic and prognostic biomarkers at an early stage. This has also prevented the identification of targets for patient-tailored immunomodulatory therapies that are both disease- and organ-selective. In this review, we discuss current knowledge of the development and functional characteristics of pathogenic T-cell-mediated immune responses in the heart, and, in particular, in myocarditis, as well as recent advances in experimental models which have the potential to translate into heart-selective immunomodulation.

LINKED ARTICLES

This article is part of a themed section on Targeting Inflammation to Reduce Cardiovascular Disease Risk. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.22/issuetoc and http://onlinelibrary.wiley.com/doi/10.1111/bcp.v82.4/issuetoc.

Myocarditis

Viral myocarditis remains a prominent infectious-inflammatory disease for patients throughout the lifespan. The condition presents several challenges including varied modes of clinical presentation, a range of timepoints when patients come to attention, a diversity of approaches to diagnosis, a spectrum of clinical courses, and unsettled perspectives on therapeutics in different patient settings and in the face of different viral pathogens. In this review, we examine current knowledge about viral heart disease and especially provide information on evolving understanding of mechanisms of disease and efforts by investigators to identify and evaluate potential therapeutic avenues for intervention.

Chronic Heart Failure and Inflammation

As a greater proportion of patients survive their initial cardiac insult, medical systems worldwide are being faced with an ever-growing need to understand the mechanisms behind the pathogenesis of chronic heart failure (HF). There is a wealth of information about the role of inflammatory cells and pathways during acute injury and the reparative processes that are subsequently activated. We discuss the different causes that lead to chronic HF development and how the sum of initial inflammatory and reparative responses only sets the trajectory for disease progression. Unfortunately, comparatively little is known about the contribution of the immune system once the trajectory has been set, and chronic HF has been established—which clinically represents the majority of patients. It is known that chronic HF is associated with circulating inflammatory cytokines that can predict clinical outcomes, yet the causative role inflammation plays in disease progression is not well defined, and the majority of clinical trials that target aspects of inflammation in patients with chronic HF have largely been negative. This review will present what is currently known about inflammation in chronic HF in both humans and animal models as a means to highlight the gap in our knowledge base that requires further examination.

Enterovirus but not Parvovirus B19 is associated with idiopathic dilated cardiomyopathy and endomyocardial CD3, CD68, or HLA-DR expression

We assessed Enterovirus (EV) &Parvovirus B19 (PVB19) genomes and CD3, CD68&HLA-DR detection in dilated cardiomyopathies (DCM). EV&PVB19 genomes and CD3, CD68&HLA-DR were detected by PCR and immunohistochemistry assays in 115 endomyocardial biopsies obtained in 13 idiopathic DCM (iDCM) and 10 explained DCM (eDCM) patients. Results were compared with those of 47 atrial surgical samples (47 surgery controls) and 22 autoptic cardiac samples (11 healthy heart controls) (2008-2014, Reims, France). EV was detected in 23.1% of iDCM patients but not in eDCM and controls (P = 0.003) (viral load 803 copies/μg). PVB19 was detected in 76.9%, 80.0%, 63.6% and 78.2% of iDCM, eDCM, healthy heart and surgery controls (P = 0.99) with a mean viral load of 413, 346, 1,428, and 71 copies/μg. CD3, CD68 or HLA-DR were detected in 100 and 50% of EV and PVB19 "mono-infected" iDCM patients. EV was exclusively detected in iDCM cases in association with CD3, CD68, or HLA-DR indicating that EV could be an etiological cause in a subset of iDCM cases. By contrast the equal frequent detection of PVB19 in iDCM cases and controls without association with CD3, CD68, or HLA-DR suggested that PVB19 could be a bystander in many DCM cases. J. Med. Virol. 89:55-63, 2017. © 2016 Wiley Periodicals, Inc.

Inflammatory Cardiomyopathy: A Current View on the Pathophysiology, Diagnosis, and Treatment

Inflammatory cardiomyopathy is defined as inflammation of the heart muscle associated with impaired function of the myocardium. In our region, its etiology is most often viral. Viral infection is a possible trigger of immune and autoimmune mechanisms which contributed to the damage of myocardial function. Myocarditis is considered the most common cause of dilated cardiomyopathy. Typical manifestation of this disease is heart failure, chest pain, or arrhythmias. The most important noninvasive diagnostic method is magnetic resonance imaging, but the gold standard of diagnostics is invasive examination, endomyocardial biopsy. In a significant proportion of cases with impaired left ventricular systolic function, recovery occurs spontaneously in several weeks and therefore it is appropriate to postpone critical therapeutic decisions about 3–6 months after start of the treatment. Therapy is based on standard heart failure treatment; immunosuppressive or antimicrobial treatment may be considered in some cases depending on the results of endomyocardial biopsy. If severe dysfunction of the left ventricle persists, device therapy may be needed.

Transitory ventricular tachycardia associated with influenza A infection of cardiac conduction tissue

PURPOSE

To describe the influence of cardiac conduction tissue infection by Influenza A virus.

METHODS AND RESULTS

A 54-year-old man with non-sustained ventricular tachycardia underwent noninvasive and invasive cardiac studies including left ventricular endomyocardial biopsy (LVEMB). Non-invasive studies showed normal cardiac parameters with no signal abnormalities. LVEMB revealed an influenza virus focal myocarditis with inflammatory infiltration of conduction tissue. Non-invasive studies showed normal cardiac parameters with preserved bi-ventricular function. CMR failed to show signal abnormalities including edema and areas of late-gadolinium enhancement. Endomyocardial biopsy (EMB) revealed an influenza virus focal lymphocytic myocarditis. Biopsy samples included sections of conduction tissue with inflammatory infiltration and cell necrosis. Therapy with oseltamivir was followed by disappearance of electrical instability at ECG and Holter monitoring.

CONCLUSION

Acute myocarditis in its arrhythmic phenotype is probably characterized by a significant inflammation of conduction tissue. Antiviral agents have an actually underestimated and potentially more contributive therapeutic role.